35w 12v GE Twist And Lock MR16

2 x 35w GE TAL50 or "twist and lock" 12v MR16 halogen lamps. One with a 18' beam angle and one with 38'.
It's interesting to note that the lamp with the wider beam angle has a frosted finish halogen capsule instead of the more usual clear.

The GU7 Twist And Lock or TAL socket is an interesting development by GE Thorn.
The MR16 halogen reflector lamp was originally developed for projection use, with the lamp being secured mechanically by the front rim of the reflector which ensured the lamp was properly located and focussed correctly. The GX5.3 pins were designed for electrical connection only.
Later, when the MR16 lamp made it's way into display lighting, the GX5.3 pins were used as a means of holding the lamp in the fitting as well as making the electrical connection, something which it was never intended for.
This caused a number of problems, for example, after a few lamp changes the lampholder would often not grip the pins correctly which could lead to arcing which welded the lamp in place or caused the lamp to drop out of the fitting altogether!
An effort to solve this problem resulted in the GU5.3 socket which featured spring clips that engaged in slots cut into the neck of the lamp for mechanical support but the problem of the pins sometimes being bent and damaged when the lamp was installed still remained.
MR16 lamps were also made with SBC bases but they were physically longer and never became popular.

GE Thorn's solution was this new GU7 twist and lock base which took inspiration from the way fluorescent lamp starters are mounted.
These TAL lamps are much easier to install and remove due to the socket naturally guiding the robust pins into the slots and the locking action ensures very good mechanical and electrical connections.
As the GU7 socket was the same size and shared the same fixing centres, any GU5.3 fitting could be retrofitted.
It's just a shame these were never more popular!